In how many ways can 10 examination papers be arranged so that the best and worst papers never come together?

In how many ways can 7 exmination paopers be arranged so that the best and the worst papers are never together?

The number of ways in which 8 examination papers be arranged so that the best and worst papers never come together is

In how many ways can 9examination papers arranged so the best and the worst papers are never together?

In how many ways can 12 papers be arranged if the best and the worst paper never come together?

In how many ways can the letters of the word BANARAS be arranged so that the letters N and S are never together

In how many types ways can five different examination papers of maths, physics, chemistry, computer an physical education be arranged so that physics and chemistry papers never come together.